1. Field of the Invention
The present invention relates to a microwave power distributor, a microwave power synthesizer, and a microwave power amplifying apparatus using the microwave power distributor and the microwave power synthesizer.
2. Description of the Prior Art
Recently, in order to ensure long service life and improve reliability and the maintainability of microwave signal amplifying apparatuses, semiconductor amplifying devices such as gallium arsenide field effect transistors (GaAs FET) have been used to replace the conventional traveling-wave tubes. In high-power capacity apparatuses, a plurality of such semiconductor amplifying devices must be provided due to the small, e.g., several watt output power of such devices. For this reason, the amplifying apparatuses must also be provided with a power distributor and power synthesizer. The power distributor splits the microwave input signal into a plurality of signals which are supplied to the semiconductor amplifying devices. The power synthesizer combines the signals amplified by the semiconductor amplifying devices to output a synthesized signal.
In conventional microwave power amplifying apparatuses, however, the power distributor, power synthesizer, and semiconductor amplifying devices are connected by coaxial cables. This results in a loss of power of high frequency microwave signals, for example, higher than 10 GHz, in the apparatus due to the increase in cable loss and the connector loss.